Polylactic Acid Resin Composition and Resin Molded Article Thereof

ABSTRACT

Provided are a polylactic acid resin composition excellent in impact resistance, migration resistance, and heat resistance, and excellent in productivity at the time of the mold forming thereof, and a resin molded article thereof. The polylactic acid resin composition includes a polylactic acid; a reaction product of at least one of a polyol and a polyol dehydration condensate, an alkylene oxide mainly formed of ethylene oxide, and a fatty acid having 12 to 24 carbon atoms; and a fatty acid amide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/570,529, filed on Dec. 14, 2011 and Japanese Application No.JP2011-271594 filed on Dec. 12, 2011, the complete disclosures of which,in their entireties, are hereby incorporated by reference.

BACKGROUND

1. Technical Field

The embodiments herein relate to a polylactic acid resin composition anda resin molded article thereof.

2. Description of the Related Art

While depletion of petroleum resources, a CO₂ reduction, and the likehave been perceived as problems, a polylactic acid using lactic acidobtained by fermenting a grain resource such as corn as a raw materialhas been attracting attention. Polylactic acid is a resin derived from aplant as described above and has the following characteristics:Polylactic acid has high rigidity, and is excellent in transparency.However, its applications have been limited as compared to an ordinaryresin because of, for example, the following reasons: Polylactic acidhas low heat resistance and low impact resistance, and hence typicallycannot be used under a high-temperature condition.

Available as a method of improving the heat resistance of the polylacticacid is, for example, a method involving increasing its crystallinitythrough a heat treatment (annealing treatment). However, the methodinvolves, for example, the following problems. The method is notpractical owing to an extremely long heat treatment time andtransparency of the polylactic acid reduces in association with progressof its crystallization.

In view of the foregoing, blending of various plasticizers and crystalnucleating agents into a resin composition using the polylactic acid asa polymer has been investigated as a method of solving those problems inrecent years.

For example, the following has been proposed as an example of theblending (Internationalt Publication No. WO2008/010318A). A fatty acidester formed of a dehydration condensate of a sugar alcohol and a fattyacid is used as the plasticizer, and a layered silicate is used as thecrystal nucleating agent.

In addition to the foregoing, for example, the following has beenproposed (Japanese Patent Application Laid-open No. JP-A-2007-130895). Asaturated ester is used as the plasticizer and an aliphatic ester or afatty acid amide is used as the crystal nucleating agent.

However, generally the applications where the resin compositiondisclosed in WO2008/010318A can be used are extremely limited owing toits low heat resistance. Moreover, the resin composition involves aproblem in that productivity at the time of its mold forming is poorbecause a molded article thereof is liable to deform upon its removalfrom the mold unless a molding time during the mold forming is set to belong.

On the other hand, the impact resistance of the resin compositiondisclosed in JP-A-2007-130895 has been somewhat improved. However, amolded article excellent in impact resistance and migration resistancetypically cannot be obtained from the resin composition because theresin composition is liable to be migrated in water or an alcohol.Further, the resin composition still has room for improvement becauseits productivity at the time of the mold forming thereof is notsufficient.

Accordingly, it would be desirable to provide a polylactic acid resincomposition excellent in impact resistance, migration resistance, andheat resistance, and excellent in productivity at the time of the moldforming thereof, and a resin molded article thereof.

SUMMARY

In view of the foregoing, an embodiment herein provides a polylacticacid resin composition, including: the following components (A) apolylactic acid; (B) a reaction product of at least one of a polyol anda polyol dehydration condensate, an alkylene oxide mainly formed ofethylene oxide, and a fatty acid having 12 to 24 carbon atoms; and (C) afatty acid amide.

Another embodiment provides a resin molded article formed of thepolylactic acid resin composition of the first gist.

The inventors of the present invention have made extensive studies toobtain a polylactic acid resin composition excellent in impactresistance, migration resistance, and heat resistance, and excellent inproductivity at the time of the mold forming thereof. As a result, theinventors of the present invention have found that the desired objectcan be achieved by the following procedure. A specific reaction product,i.e., the reaction product (component B) of at least one of the polyoland the polyol dehydration condensate, the alkylene oxide mainly formedof ethylene oxide, and the fatty acid having 12 to 24 carbon atoms isblended as a plasticizer into a resin composition using a polylacticacid as a polymer, and the fatty acid amide (component C) is furtherblended as a crystal nucleating agent into the composition.

As described above, the polylactic acid resin composition of the presentinvention contains the polylactic acid (component A), the reactionproduct (component B) of at least one of the polyol and the polyoldehydration condensate, the alkylene oxide mainly formed of ethyleneoxide, and the fatty acid having 12 to 24 carbon atoms, and the fattyacid amide (component C). Therefore, the composition is excellent inimpact resistance, migration resistance, and heat resistance, and canexert an excellent effect on its productivity at the time of the moldforming (a resin molded article thereof can be efficiently obtainedwithin a short time period without the occurrence of the deformation atthe time of its removal from the mold). In addition, the compositionexerts the following effect. The composition eliminates the need forcountermeasures against high temperatures at the time of, for example,its transportation because the composition is excellent in heatresistance and the like.

In particular, when the reaction product as the component B contains anoxyethylene group in a specific range, the polylactic acid resincomposition of the present invention and the resin molded articlethereof each become excellent in transparency, productivity at the timeof molding, and the like.

Further, when the polyol as a material for the reaction product as thecomponent (B) is a specific polyol such as glycerin, erythritol,pentaerythritol, xylitol, sorbitol, mannitol, galactitol, or maltitol,the polylactic acid resin composition of the present invention and theresin molded article thereof each become additionally excellent inimpact resistance and the like.

In addition, when the content of the reaction product as the component Bfalls within a specific range, the polylactic acid resin composition ofthe present invention and the resin molded article thereof each becomeadditionally excellent in impact resistance and the like.

In addition, when the content of the fatty acid amide as the component Cfalls within a specific range, the polylactic acid resin composition ofthe present invention and the resin molded article thereof each becomeadditionally excellent in productivity at the time of molding and thelike.

These and other aspects of the embodiments herein will be betterappreciated and understood when considered in conjunction with thefollowing description and the accompanying drawings. It should beunderstood, however, that the following descriptions, while indicatingpreferred embodiments and numerous specific details thereof, are givenby way of illustration and not of limitation. Many changes andmodifications may be made within the scope of the embodiments hereinwithout departing from the spirit thereof, and the embodiments hereininclude all such modifications.

DETAILED DESCRIPTION

The embodiments herein and the various features and advantageous detailsthereof are explained more fully with reference to the non-limitingembodiments that are illustrated in the accompanying drawings anddetailed in the following description. Descriptions of well-knowncomponents and processing techniques are omitted so as to notunnecessarily obscure the embodiments herein. The examples used hereinare intended merely to facilitate an understanding of ways in which theembodiments herein may be practiced and to further enable those of skillin the art to practice the embodiments herein. Accordingly, the examplesshould not be construed as limiting the scope of the embodiments herein.

According to the embodiments herein, the polylactic acid resincomposition contains the polylactic acid (component A), the reactionproduct (component B) of at least one of the polyol and the polyoldehydration condensate, the alkylene oxide mainly formed of ethyleneoxide, and the fatty acid having 12 to 24 carbon atoms, and the fattyacid amide (component C). In the polylactic acid resin composition ofthe present invention, the reaction product as the component (B)typically has an action as a plasticizer and the fatty acid amide as thecomponent (C) has an action as a crystal nucleating agent. It should benoted that the polylactic acid resin composition of the presentinvention can contain, for example, a resin except the polylactic acid,an inorganic filler, a hydrolysis inhibitor, an impact modifier, or anantioxidant in addition to the above-mentioned components as required.

Polylactic Acid

The polylactic acid (component A) in the polylactic acid resincomposition of the present invention refers to both of a polylactic acidobtained by subjecting only lactic acid as a raw material monomer tocondensation polymerization, and a polylactic acid obtained bysubjecting a lactic acid component and a hydroxycarboxylic acidcomponent except lactic acid (hereinafter, sometimes simply referred toas “hydroxycarboxylic acid component”) as raw material monomers tocondensation polymerization.

Optical isomers, i.e., L-lactic acid (L-form) and D-lactic acid (D-form)exist for lactic acid. Although only one of the optical isomers may, orboth the isomers may each, be incorporated as a lactic acid component inthe present invention, lactic acid having a high optical purity, thelactic acid using one of the optical isomers as a main component, ispreferably used from the viewpoints of: the achievement of compatibilitybetween the flexibility of the polylactic acid resin composition, andits rigidity and heat resistance; and productivity at the time ofmolding. It should be noted that the term “main component” as usedherein refers to a component whose content in the lactic acid componentis 80 mol % or more.

The content of the L-form or the D-form in the lactic acid component,i.e., the content of the more abundant one of the isomers in the casewhere only the lactic acid component is subjected to condensationpolymerization is preferably 95.0 mol % or more, more preferably 98 mol% or more from the above-mentioned viewpoints.

The content of the L-form or the D-form in the lactic acid component,i.e., the content of the more abundant one of the isomers in the casewhere the lactic acid component and the hydroxycarboxylic acid componentare subjected to condensation polymerization is preferably 95.0 mol % ormore, more preferably 98 mol % or more from the above-mentionedviewpoints.

In addition to a product obtained by subjecting only the D-form aslactic acid to condensation polymerization, a product obtained bysubjecting only the L-form as lactic acid to condensationpolymerization, and a product obtained by copolymerizing the D-form andthe L-form, a product obtained by blending a polylactic acid using theL-form as a main component and a polylactic acid using the D-form as amain component at arbitrary ratios may also be used as the polylacticacid.

On the other hand, examples of the hydroxycarboxylic acid componentexcept lactic acid include hydroxycarboxylic acid compounds such asglycolic acid, hydroxybutyric acid, hydroxyvaleric acid,hydroxypentanoic acid, hydroxycaproic acid, and hydroxyheptanoic acid.One kind of those hydroxycarboxylic acid components is used alone, ortwo or more kinds thereof are used in combination. Of those, glycolicacid and hydroxycaproic acid are preferred.

In addition, in the present invention, dimers of lactic acid and thehydroxycarboxylic acid compound may be incorporated into each component.For example, a lactide as a cyclic dimer of lactic acid is used as thedimer of lactic acid, and for example, glycolide as a cyclic dimer ofglycolic acid is used as the dimer of the hydroxycarboxylic acidcompound. It should be noted that the lactides are classified into anL-lactide as a cyclic dimer of L-lactic acid, a D-lactide as a cyclicdimer of D-lactic acid, a meso-lactide obtained by the cyclicdimerization of D-lactic acid and L-lactic acid, and a DL-lactide as aracemic mixture of the D-lactide and the L-lactide. Although each of thelactides can be used in the present invention, the D-lactide and theL-lactide are preferred from the viewpoints of the flexibility andrigidity of the polylactic acid resin composition, and productivity atthe time of the molding of the polylactic acid resin. It should be notedthat the dimer of lactic acid may be incorporated into the lactic acidcomponent in each of the case where only the lactic acid component issubjected to condensation polymerization, and the case where the lacticacid component and the hydroxycarboxylic acid component are subjected tocondensation polymerization.

The condensation polymerization reaction of only the lactic acidcomponent, and the condensation polymerization reaction of the lacticacid component and the hydroxycarboxylic acid component are notparticularly limited, and can each be performed by employing a knownmethod.

In addition, the weight-average molecular weight of the polylactic acidin the present invention falls within the range of typically 10,000 to400,000, preferably 50,000 to 400,000. The weight-average molecularweight more preferably falls within the range of 100,000 to 300,000.That is because of the following reasons. When the weight-averagemolecular weight of the polylactic acid falls short of the range, themechanical properties of a resin molded article are low. In contrast,when the weight-average molecular weight of the polylactic acidoutstrips the range, the polylactic acid becomes poor in flowability atthe time of the molding thereof. It should be noted that theweight-average molecular weight of the polylactic acid can be determinedin terms of styrene having a known molecular weight as a reference byusing a gel permeation chromatograph (GPC), chloroform as a solvent, ahigh-temperature SEC column (GMHHR-H series) manufactured by TOSOHCORPORATION as a column with its flow rate and column temperature set to1.0 mL/min and 40° C., respectively, and a refractive index detector(RI) as a detector.

Plasticizer

The reaction product (component B) of at least one of the polyol and thepolyol dehydration condensate, the alkylene oxide mainly formed ofethylene oxide, and the fatty acid having 12 to 24 carbon atoms is usedas the plasticizer in the polylactic acid resin composition of thepresent invention. The term “alkylene oxide mainly formed of ethyleneoxide” indicates that ethylene oxide accounts for over half of thealkylene oxide and is intended to encompass an alkylene oxide entirelyformed of ethylene oxide. It should be noted that, when an alkyleneoxide except ethylene oxide is used in combination with ethylene oxideas the alkylene oxides, for example, propylene oxide, butylene oxide, orisobutylene oxide is used in combination.

Further, the polyol as a material for the reaction product as thecomponent (B) is not particularly limited. From the viewpoints of impactresistance and the like, glycerin, erythritol, pentaerythritol, xylitol,sorbitol, mannitol, galactitol, maltitol, or the like is preferablyused.

A method of producing the reaction product (component B) is, forexample, a method involving: causing the polyol and the fatty acid toreact with each other under heating to esterify the polyol; andsubjecting ethylene oxide to an addition reaction with the resultantunder heating in an autoclave to provide the reaction product (componentB). Alternatively, after the polyol dehydration condensate and the fattyacid have been caused to react with each other so that the condensatemay be esterified, ethylene oxide may be added to the resultant in thesame manner as in the above-mentioned method. Alternatively, afterethylene oxide has been added to the polyol and the polyol dehydrationcondensate, the fatty acid may be caused to react with the resultant.Also available is, for example, a method involving: synthesizing a fattyacid ester from the fatty acid and a monohydric alcohol having a smallnumber of carbon atoms (methanol or ethanol) in advance; subjecting theester to an ester exchange reaction with the polyol and the polyoldehydration condensate; and adding ethylene oxide to the resultant inthe same manner as in the above-mentioned method to provide the reactionproduct (component B). In the polylactic acid resin composition of thepresent invention, one kind of the reaction products (components B) thusobtained is used alone, or two or more kinds thereof are used incombination.

In addition, the content of an oxyethylene group in the reaction product(component B) is preferably 20 to 95 wt %, more preferably 30 to 95 wt %from such a viewpoint that the polylactic acid resin composition of thepresent invention is excellent in transparency and impact resistance.

In addition, the reaction product (component B) may be each of asaturated ester obtained by esterifying all the hydroxyl groups of thepolyol and the polyol dehydration condensate with the fatty acid, and apartial ester obtained by esterifying part of the hydroxyl groups.

In addition, the reaction product (component B) has preferably in excessof 2 (more than 2) and 9 or less, more preferably in excess of 2.5 (morethan 2.5) and 6 or less ester groups on average in a molecule thereoffrom the viewpoint of the impact resistance.

The fatty acid having 12 to 24 carbon atoms is used in the synthesis ofthe reaction product (component B) and a fatty acid having 14 to 24carbon atoms is preferably used from such a viewpoint that thepolylactic acid resin composition of the present invention is excellentin impact resistance, and in migration resistance for water and analcohol-based solvent. That is because of the following reasons. Whenthe number of carbon atoms in the fatty acid falls short of the range,desired impact resistance is hardly obtained. Further, the amount of thecomposition to be migrated in water or the alcohol-based solventincreases. In contrast, when the number of carbon atoms in the fattyacid outstrips the range, the composition has bad compatibility with thepolylactic acid (A) as a polymer and is poor in transparency. It shouldbe noted that a fatty acid corresponding to any one of a saturated fattyacid and an unsaturated fatty acid may be used as the fatty acid, andthe fatty acids may be used in combination. Alternatively, the fattyacid may be a mixture of fatty acids transformed from oils and fats. Inthat case, a mixture whose average number of carbon atoms falls withinthe range is used.

In addition, specific examples of the reaction product (component B)include a polyoxyethylene glycerin laurate, a polyoxyethylene glycerincocoate, a polyoxyethylene glycerin myristate, a polyoxyethyleneglycerin palmitate, a polyoxyethylene glycerin linoleate, apolyoxyethylene glycerin stearate, a polyoxyethylene glycerinisostearate, a polyoxyethylene glycerin-12-hydroxystearate, apolyoxyethylene glycerin oleate, a polyoxyethylene glycerin eicosanoate,a polyoxyethylene glycerin behenate, a polyoxyethylene glycerinlignocerate, a polyoxyethylene erythritol laurate, a polyoxyethyleneerythritol cocoate, a polyoxyethylene erythritol myristate, apolyoxyethylene erythritol palmitate, a polyoxyethylene erythritollinoleate, a polyoxyethylene erythritol stearate, a polyoxyethyleneerythritol isostearate, a polyoxyethylene erythritol-12-hydroxystearate,a polyoxyethylene erythritol oleate, a polyoxyethylene erythritoleicosanoate, a polyoxyethylene erythritol behenate, a polyoxyethyleneerythritol lignocerate, a polyoxyethylene anhydroerythritol laurate, apolyoxyethylene anhydroerythritol cocoate, a polyoxyethyleneanhydroerythritol myristate, a polyoxyethylene anhydroerythritolpalmitate, a polyoxyethylene anhydroerythritol linoleate, apolyoxyethylene anhydroerythritol stearate, a polyoxyethyleneanhydroerythritol isostearate, a polyoxyethyleneanhydroerythritol-12-hydroxystearate, a polyoxyethyleneanhydroerythritol oleate, a polyoxyethylene anhydroerythritoleicosanoate, a polyoxyethylene anhydroerythritol behenate, apolyoxyethylene anhydroerythritol lignocerate, a polyoxyethylenesorbitol laurate, a polyoxyethylene sorbitol cocoate, a polyoxyethylenesorbitol myristate, a polyoxyethylene sorbitol palmitate, apolyoxyethylene sorbitol linoleate, a polyoxyethylene sorbitol stearate,a polyoxyethylene sorbitol isostearate, a polyoxyethylenesorbitol-12-hydroxystearate, a polyoxyethylene sorbitol oleate, apolyoxyethylene sorbitol eicosanoate, a polyoxyethylene sorbitolbehenate, a polyoxyethylene sorbitol lignocerate, a polyoxyethylenesorbitan laurate, a polyoxyethylene sorbitan cocoate, a polyoxyethylenesorbitan myristate, a polyoxyethylene sorbitan palmitate, apolyoxyethylene sorbitan linoleate, a polyoxyethylene sorbitan stearate,a polyoxyethylene sorbitan isostearate, a polyoxyethylenesorbitan-12-hydroxystearate, a polyoxyethylene sorbitan oleate, apolyoxyethylene sorbitan eicosanoate, a polyoxyethylene sorbitanbehenate, a polyoxyethylene sorbitan lignocerate, a polyoxyethyleneisosorbide laurate, a polyoxyethylene isosorbide cocoate, apolyoxyethylene isosorbide myristate, a polyoxyethylene isosorbidepalmitate, a polyoxyethylene isosorbide linoleate, a polyoxyethyleneisosorbide stearate, a polyoxyethylene isosorbide isostearate, apolyoxyethylene isosorbide-12-hydroxystearate, a polyoxyethyleneisosorbide oleate, a polyoxyethylene isosorbide eicosanoate, apolyoxyethylene isosorbide behenate, a polyoxyethylene isosorbidelignocerate, a polyoxyethylene mannitol laurate, a polyoxyethylenemannitol cocoate, a polyoxyethylene mannitol myristate, apolyoxyethylene mannitol palmitate, a polyoxyethylene mannitollinoleate, a polyoxyethylene mannitol stearate, a polyoxyethylenemannitol isostearate, a polyoxyethylene mannitol-12-hydroxystearate, apolyoxyethylene mannitol oleate, a polyoxyethylene mannitol eicosanoate,a polyoxyethylene mannitol behenate, a polyoxyethylene mannitollignocerate, a polyoxyethylene mannitan laurate, a polyoxyethylenemannitan cocoate, a polyoxyethylene mannitan myristate, apolyoxyethylene mannitan palmitate, a polyoxyethylene mannitanlinoleate, a polyoxyethylene mannitan stearate, a polyoxyethylenemannitan isostearate, a polyoxyethylene mannitan-12-hydroxystearate, apolyoxyethylene mannitan oleate, a polyoxyethylene mannitan eicosanoate,a polyoxyethylene mannitan behenate, a polyoxyethylene mannitanlignocerate, a polyoxyethylene isomannide laurate, a polyoxyethyleneisomannide cocoate, a polyoxyethylene isomannide myristate, apolyoxyethylene isomannide palmitate, a polyoxyethylene isomannidelinoleate, a polyoxyethylene isomannide stearate, a polyoxyethyleneisomannide isostearate, a polyoxyethylene isomannide-12-hydroxystearate,a polyoxyethylene isomannide oleate, a polyoxyethylene isomannideeicosanoate, a polyoxyethylene isomannide behenate, a polyoxyethyleneisomannide lignocerate, a polyoxyethylene xylitol laurate, apolyoxyethylene xylitol cocoate, a polyoxyethylene xylitol myristate, apolyoxyethylene xylitol palmitate, a polyoxyethylene xylitol linoleate,a polyoxyethylene xylitol stearate, a polyoxyethylene xylitolisostearate, a polyoxyethylene xylitol-12-hydroxystearate, apolyoxyethylene xylitol oleate, a polyoxyethylene xylitol eicosanoate, apolyoxyethylene xylitol behenate, a polyoxyethylene xylitol lignocerate,a polyoxyethylene anhydroxylitol laurate, a polyoxyethyleneanhydroxylitol cocoate, a polyoxyethylene anhydroxylitol myristate, apolyoxyethylene anhydroxylitol palmitate, a polyoxyethyleneanhydroxylitol linoleate, a polyoxyethylene anhydroxylitol stearate, apolyoxyethylene anhydroxylitol isostearate, a polyoxyethyleneanhydroxylitol-12-hydroxystearate, a polyoxyethylene anhydroxylitololeate, a polyoxyethylene anhydroxylitol eicosanoate, a polyoxyethyleneanhydroxylitol behenate, a polyoxyethylene anhydroxylitol lignocerate, apolyoxyethylene maltitol laurate, a polyoxyethylene maltitol cocoate, apolyoxyethylene maltitol myristate, a polyoxyethylene maltitolpalmitate, a polyoxyethylene maltitol linoleate, a polyoxyethylenemaltitol stearate, a polyoxyethylene maltitol isostearate, apolyoxyethylene maltitol-12-hydroxystearate, a polyoxyethylene maltitololeate, a polyoxyethylene maltitol eicosanoate, a polyoxyethylenemaltitol behenate, a polyoxyethylene maltitol lignocerate, apolyoxyethylene anhydromaltitol laurate, a polyoxyethyleneanhydromaltitol cocoate, a polyoxyethylene anhydromaltitol myristate, apolyoxyethylene anhydromaltitol palmitate, a polyoxyethyleneanhydromaltitol linoleate, a polyoxyethylene anhydromaltitol stearate, apolyoxyethylene anhydromaltitol isostearate, a polyoxyethyleneanhydromaltitol-12-hydroxystearate, a polyoxyethylene anhydromaltitololeate, a polyoxyethylene anhydromaltitol eicosanoate, a polyoxyethyleneanhydromaltitol behenate, a polyoxyethylene anhydromaltitol lignocerate,a polyoxyethylene galactitol laurate, a polyoxyethylene galactitolcocoate, a polyoxyethylene galactitol myristate, a polyoxyethylenegalactitol palmitate, a polyoxyethylene galactitol linoleate, apolyoxyethylene galactitol stearate, a polyoxyethylene galactitolisostearate, a polyoxyethylene galactitol-12-hydroxystearate, apolyoxyethylene galactitol oleate, a polyoxyethylene galactitoleicosanoate, a polyoxyethylene galactitol behenate, a polyoxyethylenegalactitol lignocerate, a polyoxyethylene anhydrogalactitol laurate, apolyoxyethylene anhydrogalactitol cocoate, a polyoxyethyleneanhydrogalactitol myristate, a polyoxyethylene anhydrogalactitolpalmitate, a polyoxyethylene anhydrogalactitol linoleate, apolyoxyethylene anhydrogalactitol stearate, a polyoxyethyleneanhydrogalactitol isostearate, a polyoxyethyleneanhydrogalactitol-12-hydroxystearate, a polyoxyethyleneanhydrogalactitol oleate, a polyoxyethylene anhydrogalactitoleicosanoate, a polyoxyethylene anhydrogalactitol behenate, and apolyoxyethylene anhydrogalactitol lignocerate. One kind of thosereaction products is used alone, or two or more kinds thereof are usedin combination. It should be noted that as one or a plurality of fattyacid ester groups exist in one molecule of each of the reaction productslisted above, the term “polyoxyethylene glycerin laurate”, for example,is intended to encompass “polyoxyethylene glycerin monolaurate,polyoxyethylene glycerin dilaurate, polyoxyethylene glycerin trilaurate,and the like.”

The content of the reaction product (component B) in the polylactic acidresin composition of the present invention falls within the range ofpreferably 2 to 15 parts by weight, more preferably 3 to 10 parts byweight with respect to 100 parts by weight of the polylactic acid(component A) from such a viewpoint that the composition becomesexcellent in impact resistance, productivity at the time of the moldingthereof, and the like.

Crystal Nucleating Agent

The fatty acid amide (component C) is used as the crystal nucleatingagent in the polylactic acid resin composition of the present inventionfrom the viewpoints of, for example, the moldability, heat resistance,and impact resistance of a polylactic acid resin molded article.

The fatty acid amide (component C) to be used in the present inventionmay be a fatty acid amide having a hydroxyl group, or may be a fattyacid amide free of any hydroxyl group.

Although the fatty acid amide free of any hydroxyl group is notparticularly limited, it is preferred to use, for example, any of: fattyacid monoamides such as caprylic acid amide, capric acid amide, myristicacid amide, palmitic acid amide, lauric acid amide, stearic acid amide,arachidic acid amide, behenic acid amide, lignoceric acid amide, stearicacid monoethanolamide, oleic acid amide, linoleic acid amide, andarachidonic acid amide; and fatty acid bisamides such asethylenebiscaprylic acid amide, butylenebiscaprylic acid amide,hexamethylenebiscaprylic acid amide, m-xylylenebiscaprylic acid amide,ethylenebiscapric acid amide, butylenebiscapric acid amide,hexamethylenebiscapric acid amide, m-xylylenebiscapric acid amide,ethylenebislauric acid amide, butylenebislauric acid amide,hexamethylenebislauric acid amide, m-xylylenebislauric acid amide,ethylenebisstearic acid amide, butylenebisstearic acid amide,hexamethylenebisstearic acid amide, m-xylylenebisstearic acid amide,ethylenebisarachidic acid amide, butylenebisarachidic acid amide,hexamethylenebisarachidic acid amide, m-xylylenebisarachidic acid amide,ethylenebisbehenic acid amide, butylenebisbehenic acid amide,hexamethylenebisbehenic acid amide, m-xylylenebisbehenic acid amide,ethylenebislignoceric acid amide, butylenebislignoceric acid amide,hexamethylenebislignoceric acid amide, m-xylylenebislignoceric acidamide, ethylenebisoleic acid amide, butylenebisoleic acid amide,hexamethylenebisoleic acid amide, m-xylylenebisoleic acid amide,ethylenebislinoleic acid amide, butylenebislinoleic acid amide,hexamethylenebislinoleic acid amide, m-xylylenebislinoleic acid amide,ethylenebisarachidonic acid amide, butylenebisarachidonic acid amide,hexamethylenebisarachidonic acid amide, and m-xylylenebisarachidonicacid amide, because they may impart excellent impact resistance to thepolylactic acid resin composition of the present invention. It should benoted that one kind of those fatty acid amides is used alone, or two ormore kinds thereof are used in combination.

In addition, for example, a bisamide compound obtained by causing afatty acid having 8 to 24 carbon atoms, the fatty acid having a hydroxylgroup, and a compound having two amino groups to react with each otheris preferably used as the fatty acid amide having a hydroxyl groupbecause the polylactic acid resin composition of the present inventionbecomes excellent in transparency and the like. It should be noted thata fatty acid corresponding to any one of a saturated fatty acid and anunsaturated fatty acid may be used as the fatty acid, and the fattyacids may be used in combination. Alternatively, the fatty acid may be amixture of fatty acids transformed from oils and fats. In that case, amixture whose average number of carbon atoms falls within the range isused.

In addition, specific examples of the fatty acid amide having a hydroxylgroup include: hydroxyl group-containing fatty acid monoamides such as8-hydroxycaprylic acid amide, 10-hydroxylauric acid amide,10-hydroxycapric acid amide, 11-hydroxymyristic acid amide,16-hydroxypalmitic acid amide, 12-hydroxystearic acid amide,2-hydroxyarachidic acid amide, 2-hydroxybehenic acid amide,2-hydroxylignoceric acid amide, 12-hydroxystearic acid monoethanolamide,12-hydroxyoleic acid amide, 11-hydroxylinoleic acid amide, and2-hydroxyarachidonic acid amide; and hydroxyl group-containing fattyacid bisamides such as N,N′-ethylenebis-8-hydroxycapric acid amide,N,N′-butylenebis-8-hydroxycapric acid amide,N,N′-hexamethylenebis-8-hydroxycapric acid amide,N,N′-m-xylylenebis-8-hydroxycapric acid amide,N,N′-ethylenebis-10-hydroxylauric acid amide,N,N′-butylenebis-10-hydroxylauric acid amide,N,N′-hexamethylenebis-10-hydroxylauric acid amide,N,N′-m-xylylenebis-10-hydroxylauric acid amide,N,N′-ethylenebis-11-hydroxymyristic acid amide,N,N′-butylenebis-11-hydroxymyristic acid amide,N,N′-hexamethylenebis-11-hydroxymyristic acid amide,N,N′-m-xylylenebis-11-hydroxymyristic acid amide,N,N′-ethylenebis-16-hydroxypalmitic acid amide,N,N′-butylenebis-16-hydroxypalmitic acid amide,N,N′-hexamethylenebis-16-hydroxypalmitic acid amide,N,N′-m-xylylenebis-16-hydroxypalmitic acid amide,N,N′-ethylenebis-12-hydroxystearic acid amide,N,N′-butylenebis-12-hydroxystearic acid amide,N,N′-hexamethylenebis-12-hydroxystearic acid amide,N,N′-m-xylylenebis-12-hydroxystearic acid amide,N,N′-ethylenebis-2-hydroxyarachidic acid amide,N,N′-butylenebis-2-hydroxyarachidic acid amide,N,N′-hexamethylenebis-2-hydroxyarachidic acid amide,N,N′-m-xylylenebis-2-hydroxyarachidic acid amide,N,N′-ethylenebis-2-hydroxybehenic acid amide,N,N′-butylenebis-2-hydroxybehenic acid amide,N,N′-hexamethylenebis-2-hydroxybehenic acid amide,N,N′-m-xylylenebis-2-hydroxybehenic acid amide,N,N′-ethylenebis-2-hydroxylignoceric acid amide,N,N′-butylenebis-2-hydroxylignoceric acid amide,N,N′-hexamethylenebis-2-hydroxylignoceric acid amide,N,N′-m-xylylenebis-2-hydroxylignoceric acid amide,N,N′-ethylenebis-12-hydroxyoleic acid amide,N,N′-butylenebis-12-hydroxyoleic acid amide,N,N′-hexamethylenebis-12-hydroxyoleic acid amide,N,N′-m-xylylenebis-12-hydroxyoleic acid amide,N,N′-ethylenebis-11-hydroxylinoleic acid amide,N,N′-butylenebis-11-hydroxylinoleic acid amide,N,N′-hexamethylenebis-11-hydroxylinoleic acid amide,N,N′-m-xylylenebis-11-hydroxylinoleic acid amide,N,N′-ethylenebis-11-hydroxyarachidonic acid amide,N,N′-butylenebis-11-hydroxyarachidonic acid amide,N,N′-hexamethylenebis-11-hydroxyarachidonic acid amide, andN,N′-m-xylylenebis-11-hydroxyarachidonic acid amide. One kind of thosefatty acid amides is used alone, or two or more kinds thereof are usedin combination.

The content of the fatty acid amide (component C) in the polylactic acidresin composition of the present invention falls within the range ofpreferably 0.1 to 2 parts by weight with respect to 100 parts by weightof the polylactic acid (component A) from such a viewpoint that thecomposition becomes excellent in productivity at the time of the moldingand the like.

Other Resin

In addition to the components (A) to (C), any other resin may beappropriately incorporated into the polylactic acid resin composition ofthe present invention as long as an effect of the present invention isnot impaired (i.e., in the range of less than 20 wt %, preferably 1 to15 wt %, more preferably 1 to 10 wt % of the whole polylactic acid resincomposition). Examples of the other resin include: thermoplastic resinssuch as a polypropylene, a polystyrene, an ABS resin, an AS resin, apolyphenylene sulfide, a polyetheretherketone, a polyester, apolyacetal, a polysulfone, a polyphenylene oxide, and a polyetherimide;and thermosetting resins such as a phenol resin, a melamine resin, anunsaturated polyester resin, a silicone resin, and an epoxy resin. Onekind of those resins is used alone, or two or more kinds thereof areused in combination.

Inorganic Filler

Further, an inorganic filler may be incorporated into the polylacticacid resin composition of the present invention as required. Specificexamples of the inorganic filler include talc, clay, mica, zeolite,bentonite, montmorillonite, a glass fiber, and a carbon fiber. One kindof those inorganic fillers is used alone, or two or more kinds thereofare used in combination.

In addition, the content of the inorganic filler in the polylactic acidresin composition of the present invention falls within the range ofpreferably 0.01 to 2 parts by weight, more preferably 0.01 to 1 part byweight with respect to 100 parts by weight of the polylactic acid(component A) from such a viewpoint that the composition becomesexcellent in impact resistance, bending strength, and the like.

Hydrolysis Inhibitor

In addition, a hydrolysis inhibitor may be incorporated into thepolylactic acid resin composition of the present invention as required.Examples of the hydrolysis inhibitor include carbodiimide compounds suchas a polycarbodiimide compound and a monocarbodiimide compound. Ofthose, a polycarbodiimide compound is preferred from the viewpoint ofthe moldability of the polylactic acid resin molded article, and amonocarbodiimide compound is more preferred from the viewpoints of theheat resistance, moldability, flowability, and impact resistance of thepolylactic acid resin molded article, and the blooming resistance of thecrystal nucleating agent.

Examples of the polycarbodiimide compound include apoly(4,4′-diphenylmethanecarbodiimide), apoly(4,4′-dicyclohexylmethanecarbodiimide), apoly(1,3,5-triisopropylbenzene)polycarbodiimide, and apoly(1,3,5-triisopropylbenzene and1,5-diisopropylbenzene)polycarbodiimide. The monocarbodiimide compoundis, for example, N,N′-di-2,6-diisopropylphenylcarbodiimide.

In addition, the content of the hydrolysis inhibitor in the polylacticacid resin composition of the present invention falls within the rangeof preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1 partby weight with respect to 100 parts by weight of the polylactic acid(component A) from the viewpoint of the moldability of the polylacticacid resin molded article.

Impact Modifier

In addition, an impact modifier may be incorporated into the polylacticacid resin composition of the present invention as required from theviewpoints of improvements in its physical properties such asflexibility. A (meth)acrylic acid polymer, an ethylene-(meth)acrylicacid copolymer, an ethylene-alkyl (meth)acrylate copolymer, anepoxy-modified silicone acrylic rubber, a copolymer of a diene and avinyl monomer, and a hydrogenated product thereof, organic fibers suchas an aromatic polyamide fiber, a diene rubber, a compatibilizer, andthe like can each be used as the impact modifier. It should be notedthat the term “(meth)acrylic acid” refers to acrylic acid and/ormethacrylic acid.

In addition, the content of the impact modifier in the polylactic acidresin composition of the present invention falls within the range ofpreferably 1 to 20 parts by weight, more preferably 3 to 10 parts byweight with respect to 100 parts by weight of the polylactic acid(component A) from the viewpoints of the impact resistance andmoldability of the resin composition.

The polylactic acid resin composition of the present invention cancontain a flame retardant, an antioxidant, a lubricant, an antistaticagent, an anti-fogging agent, a light stabilizer, a UV absorber, apigment, a colorant, an antifungal agent, an antibacterial agent, afoaming agent, or the like as any other component except the foregoingto such an extent that the achievement of the object of the presentinvention is not impaired.

Production Of Polylactic Acid Resin Composition and Resin Molded ArticleThereof.

The polylactic acid resin composition of the present invention can beprepared by: blending the polylactic acid (component A), the specificreaction product (component B) as a plasticizer, and the fatty acidamide (component C) as a crystal nucleating agent, and as required, anyother material at predetermined ratios; and melting and mixing thematerials at 160 to 240° C. It should be noted that the melting andmixing may be performed after the respective materials have beenblended. Alternatively, the composition may be prepared by the followingprocedure. After the polylactic acid (component A) has been previouslymelted with an extruder, a Banbury mixer, a kneader, a heating roll, orthe like, the other materials are blended into the molten product andthen the mixture is shaped into a uniform pellet shape.

Then, a resin molded article can be obtained by using the resincomposition melted and mixed as described above as a material throughcast molding, injection molding, blow molding, extrusion molding, or thelike. In addition, the composition can be molded into various moldedarticles by molding methods such as vacuum molding, pressure molding,and vacuum pressure molding after the composition has been processedinto a sheet.

When the composition is formed with a mold for obtaining the resinmolded article, the temperature of the mold at the time of the moldingfalls within the range of preferably 40 to 140° C., more preferably 70to 120° C. from the viewpoint of productivity. In addition, the timeperiod for which the resin molded article is held in the mold in vacuummolding, pressure molding, or vacuum pressure molding is preferably 1 to15 seconds, more preferably 1 to 10 seconds from the viewpoints ofproductivity and the like.

In addition, the migration amount of the polylactic acid resin moldedarticle of the present invention was measured in accordance with amigration test method specified in the FCN system concerning a foodpackaging container of the U.S. Food and Drug Administration (FDA), andthen its cumulative estimated daily intake (CEDI) was calculated.Smaller values for the migration amount and the CEDI mean that themigration amount from the molded article is smaller (the molded articleis more excellent in migration resistance). The CEDI's of the polylacticacid resin composition of the present invention and the molded articlethereof can each be suppressed to less than 1 ppm, preferably less than0.5 ppm. As described above, their CEDI's are low, and hence the resincomposition and the molded article show low migration amounts at thetime of their use and can be safely used as food packaging containers.In addition, reductions in physical properties of the resin compositionand the molded article are suppressed because their migration amountsare small.

As described above, each of the polylactic acid resin composition of thepresent invention and the resin molded article thereof is excellent inimpact resistance, heat resistance, and the like, and has highbiodegradability. Accordingly, the polylactic acid resin composition ofthe present invention and the resin molded article thereof can besuitably utilized in applications including: various disposablecontainers (e.g., food containers such as a tray for fresh food, aninstant food container, a fast food container, a lunch box, a beveragebottle, and a container for a flavor such as mayonnaise, an agriculturaland horticultural container such as a seedling pot, a blister packcontainer, and a press-through pack container); CD cases; clear filefolders; cards such as a credit card; dinnerware such as a spoon and adrinking straw; plastic models; various resin products such as a resinsheet, a resin film, and a resin hose; and textile goods such as a fiberfor clothing and a nonwoven fabric. Further, the polylactic acid resincomposition of the present invention can be suitably utilized in widerfields than a conventional polylactic acid resin composition is becauseits impact resistance, heat resistance, and the like have been improvedas compared with those of the conventional polylactic acid resincomposition.

EXAMPLES

Next, examples are described together with comparative examples.However, the present invention is not limited to these examples.

First, the following materials were prepared prior to the examples andthe comparative examples.

Polylactic Acid A-1

Polylactic acid (trade name: 4032D, manufactured by Natureworks LLC)

Plasticizer B-1

Polyoxyethylene sorbitan tristearate (content of oxyethylene group: 48wt %, SOLGEN TW-65 manufactured by DAI-ICHI KOGYO SEIYAKU CO., LTD.)

Plasticizer B-2

Polyoxyethylene sorbitan tribehenate (content of oxyethylene group: 43wt %)

Plasticizer B-3

Polyoxyethylene triisostearic acid hardened castor oil (content ofoxyethylene group: 34 wt %, trade name: EMALEX RWIS-320, manufactured byNIHON EMULSION Co., Ltd.)

Plasticizer B-4

Polyoxyethylene glycerin triisostearate (content of oxyethylene group:50 wt %, trade name: EMALEX GWIS-320, manufactured by NIHON EMULSIONCo., Ltd.)

Plasticizer B-5

Polyoxyethylene sorbitol tetraoleate (content of oxyethylene group: 52%,trade name: RHEODOL 430V, manufactured by Kao Corporation)

Plasticizer B-6

Polyoxyethylene mannitan tristearate (content of oxyethylene group: 48wt %)

Plasticizer B-7

Polyoxyethylene sorbitan tristearate (content of oxyethylene group: 31wt %, prepared by DAI-ICHI KOGYO SEIYAKU CO., LTD.)

Plasticizer B-8

Polyoxyethylene sorbitan tristearate (content of oxyethylene group: 65wt %)

Plasticizer B-9

Polyoxyethylene glycerin tristearate (content of oxyethylene group: 20wt %)

Plasticizer B-10

Polyoxyethylene sorbitan tri-12-hydroxystearate (content of oxyethylenegroup: 48 wt %)

Plasticizer b-1

Ester compound formed of adipic acid, benzyl alcohol, and diethyleneglycol monomethyl ether (content of oxyethylene group: 26 wt %, tradename: DAIFATTY-101, manufactured by DAIHACHI CHEMICAL INDUSTRY CO.,LTD.)

Plasticizer b-2

Glycerin monostearate (content of oxyethylene group: 0 wt %, trade name:EXCEL S-95, manufactured by Kao Corporation)

Plasticizer b-3

Diester formed of succinic acid and triethylene glycol monomethyl ether(content of oxyethylene group: 43 wt %)

Plasticizer b-4

Polyoxyethylene glycerin tricaprylate (content of oxyethylene group: 20wt %)

Plasticizer b-5

Fatty acid ester of polyglycerin (content of oxyethylene group: 0 wt %,trade name: CHIRABAZOL VR-05, manufactured by Taiyo Kagaku Co., Ltd.)

Crystal Nucleating Agent C-1

N,N′-Ethylenebisstearic acid amide (trade name: ITOHWAX J-550S,manufactured by ITOH OIL CHEMICALS CO., LTD.)

Crystal Nucleating Agent C-2

N,N′-Ethylenebis-12-hydroxystearic acid amide (trade name: ITOHWAXJ-530, manufactured by ITOH OIL CHEMICALS CO., LTD.)

Crystal Nucleating Agent C-3

N,N′-Xylylenebis-12-hydroxystearic acid amide (trade name: ITOHWAXJ-700, manufactured by ITOH OIL CHEMICALS CO., LTD.)

Crystal Nucleating Agent C-4

N′-Hydroxyethyl-12-hydroxystearylamide (trade name: ITOHWAX J-420,manufactured by ITOH OIL CHEMICALS CO., LTD.)

Crystal Nucleating Agent c-1

Talc (trade name: MICRO ACE P-6, manufactured by Nippon Talc Co., Ltd.)

Crystal Nucleating Agent c-2

Montmorillonite, in which an ion between layers is substituted by adioctadecyldimethylammonium ion (trade name: S-BEN W, manufactured byHOJUN CO., LTD.)

Antioxidant D-1

Hindered phenolic antioxidant (trade name: IRGANOX 1076, manufactured byBASF)

Examples 1 to 18 and Comparative Examples 1 to 9

The respective materials were blended at ratios shown in Table 1 toTable 3 below, and then the mixtures were heated and kneaded with abiaxial extruder (KZW20-30MG manufactured by TECHNOVEL CORPORATION)under the condition of a temperature of its cylinder of 160 to 190° C.Thus, pellets of resin compositions were obtained. It should be notedthat the pellets were dried under reduced pressure at a temperature of70° C. for 12 hours or more.

The polylactic acid resin compositions (pellets) of the examples and thecomparative examples thus obtained were measured and evaluated for theirrespective characteristics in accordance with the following criteria.Table 1 to Table 3 below show the results together.

Mold Holding Time

A sheet having a thickness of 0.4 mm was produced from each of thepellets with a T-die extruder (manufactured by TECHNOVEL CORPORATION).After that, the sheet was heated from above and below with an infraredheater at about 300° C. to be softened. Subsequently, the sheet wasloaded into a mold with its temperature controlled to 90° C., and wasthen subjected to vacuum pressure molding, followed by removal from themold. Thus, a resin molded article was obtained. During the removal fromthe mold, the shortest time required for the resin molded article to betaken out of the mold without any deformation (mold holding time) wasmeasured. It should be noted that productivity becomes higher as theshortest time shortens.

Heat Resistance

The resin molded article (molded article formed of the polylactic acidresin composition) obtained by such mold forming as described above wasloaded into an oven at 90° C. and held for 30 minutes. Then, the moldedarticle was evaluated as ∘ when no deformation was observed after theheating, or was evaluated as x when the molded article deformed afterthe heating.

Impact Resistance

A falling ball impact test was performed by: mounting a point of impactwhose tip was of a spherical shape having a diameter of 10 mm on theresin molded article obtained by such mold forming as described above;and dropping a weight having a mass of 300 g or 500 g on the point ofimpact. Then, the altitude (mm) from which the weight was dropped whenthe resin molded article cracked was measured. It should be noted thatthe resin molded article was represented as “>1,000” in the case wherethe resin molded article did not crack even when the altitude from whichthe weight was dropped exceeded 1,000 mm, or was represented as “<50” inthe case where the resin molded article cracked even when the altitudefrom which the weight was dropped was less than 50 mm

CEDI

The migration amount of the resin molded article (molded article formedof the polylactic acid resin composition) obtained by such mold formingas described above was measured in accordance with a migration testmethod specified in the FCN system of the FDA of America, and then itscumulative estimated daily intake (CEDI) was calculated. It should benoted that in the migration test, 10% ethanol was used as a foodsimulant, and was heated under the conditions of 66° C. and 2 hours.Then, the migration amount was determined by quantifying a substancemigrated in the food simulant through gas chromatography, followed bythe calculation of the CEDI (ppm). It should be noted that a smallervalue for the CEDI means that the resin molded article is more excellentin migration resistance.

TABLE 1 Part(s) by weight Example 1 2 3 4 5 6 7 8 9 Polylactic acid A-1100 100 100 100 100 100 100 100 100 Plasticizer B-1 5 — — — — — — — —B-2 — 5 — — — — — — — B-3 — — 5 — — — — — — B-4 — — — 5 — — — — — B-5 —— — — 5 — — — — B-6 — — — — — 5 — — — B-7 — — — — — — 5 — — B-8 — — — —— — — 5 — B-9 — — — — — — — — 5 B-10 — — — — — — — — — Crystal C-1 1 1 11 1 1 1 1 1 nucleating agent C-2 — — — — — — — — — C-3 — — — — — — — — —C-4 — — — — — — — — — Antioxidant D-1 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.30.3 Mold holding time (s) 5 5 5 5 5 5 5 5 5 Heat resistance ∘ ∘ ∘ ∘ ∘ ∘∘ ∘ ∘ Impact Weight 300g >1,000 >1,000 >1,000 >1,000 >1,000 >1,000 >1,000 900 >1,000 resistance(mm) Weight 500 g 500 550 600 400 400 500 600 400 >1,000 CEDI (ppm) 0.140.13 0.15 0.12 0.16 0.13 0.16 0.12 0.10

TABLE 2 Part(s) by weight Example 10 11 12 13 14 15 16 17 18 Polylacticacid A-1 100 100 100 100 100 100 100 100 100 Plasticizer B-1 — 5 5 5 5 53 10 15 B-2 — — — — — — — — — B-3 — — — — — — — — — B-4 — — — — — — — —— B-5 — — — — — — — — — B-6 — — — — — — — — — B-7 — — — — — — — — — B-8— — — — — — — — — B-9 — — — — — — — — — B-10 5 — — — — — — — — CrystalC-1 1 — — — 0.1 2 1 1 1 nucleating agent C-2 — 1 — — — — — — — C-3 — — 1— — — — — — C-4 — — — 1 — — — — — Antioxidant D-1 0.3 0.3 0.3 0.3 0.30.3 0.3 0.3 0.3 Mold holding time (s) 5 5 5 5 5 5 5 5 5 Heat resistance∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ Impact Weight 300g >1,000 >1,000 >1,000 >1,000 >1,000 >1,000 900 >1,000 >1,000 resistance(mm) Weight 500 g 550 500 500 500 500 550 400 >1,000 >1,000 CEDI (ppm)0.13 0.13 0.13 0.13 0.13 0.13 0.10 0.23 0.34

TABLE 3 Part(s) by weight Comparative Example 1 2 3 4 5 6 7 8 9Polylactic acid A-1 100 100 100 100 100 100 100 100 100 Plasticizer B-1— — — — — — — 5 5 b-1 — 5 — — — — — — — b-2 — — 5 — — — — — — b-3 — — —5 — — — — — b-4 — — — — 5 — — — — b-5 — — — — — 5 — — — Crystalnucleating agent C-1 — 1 1 1 1 1 1 — — c-1 — — — — — — — 1 — c-2 — — — —— — — — 1 Antioxidant D-1 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Moldholding time (s) 600 10 25 10 10 15 30 30 30 Heat resistance ∘ ∘ ∘ ∘ ∘ ∘∘ x x Impact Weight 300 g 250 250 250 250 700 >1,000 250 700 600resistance (mm) Weight 500 g <50 <50 <50 <50 200 400 <50 150 150 CEDI(ppm) 0.01 1.71 3.44 3.24 1.13 0.25 0.01 0.13 0.13

As can be seen from the results of Table 1 to Table 3, the polylacticacid resin compositions of the examples each had high productivitybecause their mold holding times were shorter than those of thepolylactic acid resin compositions of the comparative examples. Further,the polylactic acid resin compositions of the examples were eachexcellent in heat resistance because none of the resin molded articlesthereof showed deformation due to heating. In addition, the polylacticacid resin compositions of the examples were each superior in impactresistance to the polylactic acid resin compositions of the comparativeexamples.

The polylactic acid resin composition of the present invention and theresin molded article thereof can be suitably utilized in applicationsincluding: various disposable containers (e.g., food containers such asa tray for fresh food, an instant food container, a fast food container,a lunch box, a beverage bottle, and a container for a flavor such asmayonnaise, an agricultural and horticultural container such as aseedling pot, a blister pack container, and a press-through packcontainer); CD cases; clear file folders; cards such as a credit card;dinnerware such as a spoon and a drinking straw; plastic models; variousresin products such as a resin sheet, a resin film, and a resin hose;and textile goods such as a fiber for clothing and a nonwoven fabric.Further, the polylactic acid resin composition of the present inventioncan be suitably utilized in wider fields than a conventional polylacticacid resin composition is because its impact resistance, heatresistance, and the like have been improved as compared with those ofthe conventional polylactic acid resin composition.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the embodiments herein that others can, byapplying current knowledge, readily modify and/or adapt for variousapplications such specific embodiments without departing from thegeneric concept, and, therefore, such adaptations and modificationsshould and are intended to be comprehended within the meaning and rangeof equivalents of the disclosed embodiments. It is to be understood thatthe phraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while the embodimentsherein have been described in terms of preferred embodiments, thoseskilled in the art will recognize that the embodiments herein can bepracticed with modification within the spirit and scope of the appendedclaims.

What is claimed is:
 1. A polylactic acid resin composition comprising: a first component comprising a polylactic acid; a second component comprising a reaction product of at least one of a polyol and a polyol dehydration condensate, an alkylene oxide mainly formed of ethylene oxide, and a fatty acid having 12 to 24 carbon atoms; and a third component comprising a fatty acid amide.
 2. The polylactic acid resin composition according to claim 1, wherein the reaction product as said second component contains 20 to 95 wt % of an oxyethylene group.
 3. The polylactic acid resin composition according to claim 1, wherein the polyol as a material for the reaction product as said second component comprises at least one component selected from the group consisting of glycerin, erythritol, pentaerythritol, xylitol, sorbitol, mannitol, galactitol, and maltitol.
 4. The polylactic acid resin composition according to claim 2, wherein the polyol as a material for the reaction product as said second component comprises at least one component selected from the group consisting of glycerin, erythritol, pentaerythritol, xylitol, sorbitol, mannitol, galactitol, and maltitol.
 5. The polylactic acid resin composition according to claim 1, wherein a content of said second component falls within a range of 2 to 15 parts by weight with respect to 100 parts by weight of said first component.
 6. The polylactic acid resin composition according to claim 2, wherein a content of said second component falls within a range of 2 to 15 parts by weight with respect to 100 parts by weight of said first component.
 7. The polylactic acid resin composition according to claim 3, wherein a content of said second component falls within a range of 2 to 15 parts by weight with respect to 100 parts by weight of said first component.
 8. The polylactic acid resin composition according to claim 4, wherein a content of said second component falls within a range of 2 to 15 parts by weight with respect to 100 parts by weight of said first component.
 9. The polylactic acid resin composition according to claim 1, wherein a content of said third component falls within a range of 0.1 to 2 parts by weight with respect to 100 parts by weight of said first component.
 10. The polylactic acid resin composition according to claim 2, wherein a content of said third component falls within a range of 0.1 to 2 parts by weight with respect to 100 parts by weight of said first component.
 11. The polylactic acid resin composition according to claim 3, wherein a content of said third component falls within a range of 0.1 to 2 parts by weight with respect to 100 parts by weight of said first component.
 12. The polylactic acid resin composition according to claim 4, wherein a content of said third component falls within a range of 0.1 to 2 parts by weight with respect to 100 parts by weight of said first component.
 13. A resin molded article comprising a polylactic acid resin composition comprising: a first component comprising a polylactic acid; a second component comprising a reaction product of at least one of a polyol and a polyol dehydration condensate, an alkylene oxide mainly formed of ethylene oxide, and a fatty acid having 12 to 24 carbon atoms; and a third component comprising a fatty acid amide.
 14. The resin molded article according to claim 13, wherein the reaction product as said second component contains 20 to 95 wt % of an oxyethylene group.
 15. The resin molded article according to claim 13, wherein the polyol as a material for the reaction product as said second component comprises at least one component selected from the group consisting of glycerin, erythritol, pentaerythritol, xylitol, sorbitol, mannitol, galactitol, and maltitol.
 16. The resin molded article according to claim 14, wherein the polyol as a material for the reaction product as said second component comprises at least one component selected from the group consisting of glycerin, erythritol, pentaerythritol, xylitol, sorbitol, mannitol, galactitol, and maltitol. 